Gate driving circuit and display device having the same

Abstract

A gate driving circuit includes a shift register configured to generate a plurality of output signals based on at least one clock signal, a plurality of output buffers configured to generate a plurality of gate signals by amplifying the output signals and to sequentially output the gate signals to a plurality of gate lines in a display panel, a detector configured to sequentially sense the gate signals and to compare each of the gate signals to a reference voltage, and a dummy output buffer configured to be coupled between the shift register and a gate line of the gate lines instead of an output buffer of the output buffers when a voltage level of a corresponding gate signal from the output buffers is less than a voltage level of the reference voltage.

What is claimed is: 
     
       1. A gate driving circuit comprising:
 a shift register configured to generate a plurality of output signals based on at least one clock signal; 
 a plurality of output buffers configured to generate a plurality of gate signals by amplifying the output signals and to sequentially output the gate signals to a plurality of gate lines in a display panel; 
 a detector configured to sequentially sense the gate signals and to compare each of the gate signals to a reference voltage; and 
 a dummy output buffer configured to be coupled between the shift register and a gate line of the gate lines instead of an output buffer of the output buffers when a voltage level of a corresponding gate signal from the output buffer is less than a voltage level of the reference voltage. 
 
     
     
       2. The gate driving circuit of  claim 1 , wherein each of the output buffers comprises:
 an amplifier configured to generate a corresponding gate signal by amplifying a corresponding output signal; 
 a first switch coupled between the shift register and the amplifier; and 
 a second switch coupled between the amplifier and a corresponding gate line. 
 
     
     
       3. The gate driving circuit of  claim 2 , wherein the dummy output buffer comprises:
 a dummy amplifier configured to generate the gate signal by amplifying the output signal; 
 a third switch coupled between the shift register and the dummy amplifier; 
 a fourth switch coupled between the dummy amplifier and the gate line; and 
 a fifth switch coupled between the dummy amplifier and the gate line. 
 
     
     
       4. The gate driving circuit of  claim 3 , wherein the detector comprises:
 a comparator configured to compare each of the gate signals output from the output buffers to the reference voltage; 
 a sixth switch coupled between the output buffers and the comparator; and 
 a buffer controller configured to generate a buffer control signal to control the first through fifth switches based on an output of the comparator. 
 
     
     
       5. The gate driving circuit of  claim 4 , wherein when the voltage level of the gate signal from the output buffer is greater than or equal to the voltage level of the reference voltage, the first switch of the output buffer and the second switch of the output buffer turn on based on the buffer control signal. 
     
     
       6. The gate driving circuit of  claim 4 , wherein when the voltage level of the gate signal from the output buffer is less than the voltage level of the reference voltage, the third switch, the fourth switch, and the fifth switch turn on based on the buffer control signal. 
     
     
       7. The gate driving circuit of  claim 4 , wherein the detector is configured to sense each of the gate signals output from the output buffers when the sixth switch turns on. 
     
     
       8. The gate driving circuit of  claim 4 , wherein the first through fifth switches are p-channel metal oxide semiconductor transistors. 
     
     
       9. The gate driving circuit of  claim 4 , wherein the first through fifth switches are n-channel metal oxide semiconductor transistors. 
     
     
       10. The gate driving circuit of  claim 4 , wherein the first switch and the second switch are p-channel metal oxide semiconductor transistors, and the third switch, the fourth switch, and the fifth switch are n-channel metal oxide semiconductor transistors. 
     
     
       11. The gate driving circuit of  claim 4 , wherein the first switch and the second switch are n-channel metal oxide semiconductor transistors, and the third switch, the fourth switch, and the fifth switch are p-channel metal oxide semiconductor transistors. 
     
     
       12. A display device comprising:
 a display panel comprising a plurality of gate lines, a plurality of data lines, and a plurality of pixels; 
 a gate driver configured to provide a plurality of gate signals to the pixels through the gate lines; 
 a data driver configured to provide a plurality of data signals to the pixels through the data lines; and 
 a timing controller configured to generate a plurality of control signals to control the gate driver and the data driver, 
 wherein the gate driver comprises: 
 a shift register configured to generate a plurality of output signals based on at least one clock signal; 
 a plurality of output buffers configured to generate the gate signals and sequentially output the gate signals to the gate lines; 
 a detector configured to sequentially sense the gate signals and compare each of the gate signals to a reference voltage; and 
 a dummy output buffer configured to be coupled between the shift register and a gate line of the gate lines instead of an output buffer of the output buffers when a voltage level of a corresponding gate signal from the output buffer is less than a voltage level of the reference voltage. 
 
     
     
       13. The display device of  claim 12 , wherein each of the output buffers comprises:
 an amplifier configured to generate a corresponding gate signal by amplifying a corresponding output signal; 
 a first switch coupled between the shift register and the amplifier; and 
 a second switch coupled between the amplifier and a corresponding gate line. 
 
     
     
       14. The display device of  claim 13 , wherein the dummy output buffer comprises:
 a dummy amplifier configured to generate the gate signal by amplifying the output signal; 
 a third switch coupled between the shift register and the dummy amplifier; 
 a fourth switch coupled between the dummy amplifier and the gate line; and 
 a fifth switch coupled between the dummy amplifier and the gate line. 
 
     
     
       15. The display device of  claim 14 , wherein the detector comprises:
 a comparator configured to compare each of the gate signals output from the output buffers to the reference voltage; 
 a sixth switch coupled between the output buffers and the comparator; and 
 a buffer controller configured to generate a buffer control signal to control the first through fifth switches based on an output of the comparator. 
 
     
     
       16. The display device of  claim 15 , wherein when the voltage level of the gate signal from the output buffer is greater than or equal to the voltage level of the reference voltage, the first switch of the output buffer and the second switch of the output buffer turn on based on the buffer control signal. 
     
     
       17. The display device of  claim 15 , wherein when the voltage level of the gate signal from the output buffer is less than the voltage level of the reference voltage, the third switch, the fourth switch, and the fifth switch turn on based on the buffer control signal. 
     
     
       18. The display device of  claim 15 , wherein the detector is configured to sense each of the gate signals output from the output buffers when the sixth switch turns on. 
     
     
       19. The display device of  claim 15 , wherein the detector is configured to sense each of the gate signals output from the output buffers at a power-on timing of the display device. 
     
     
       20. The display device of  claim 15 , wherein the detector is configured to sense each the gate signals output from the output buffers during a vertical blank period in a frame.